This invention relates generally to geodetic ground control and more particularly to a system that provides a rapid accurate means for extending geodetic control.
Normally, the extension of geodetic control requires a substantial amount of time. Two processes must take place which are mutually exclusive and sequentially enacted. Where the extension is substantial, the first step is to establish a number of easily distinguishable known points on the ground, in the area where the control is to be extended. Once this very time consuming work is finished the area is photographed and a photogrammetric analysis made of the area and accurate maps produced from the information.
There are circumstances however, where the initial survey work cannot be performed. For example, if the area is owned or occuppied by persons hostile to the extension of geodetic control, where the terrain is of a nature that it is impractical to perform an accurate survey or where time is such an important factor it would be impossible to conduct a formal precision survey.
In some instances electronic beacons and ground control stations are utilized to guide aircraft. These devices may be placed in remote areas by helicopter or dropped by parachute. It is necessary that these systems along with an aircraft system be calibrated in both real time and non real time. It is also necessary that excessive bias errors be removed and precise location and altitude of terrain features determined.
The system proposed hereinafter eliminates the inadequacies and difficulties of the devices and systems used to date, called the prior art.